/**
 * Alipay.com Inc.
 * Copyright (c) 2004-2011 All Rights Reserved.
 */
package com.liwei.nio.mina;

import java.nio.charset.Charset;

import org.apache.mina.core.buffer.BufferDataException;
import org.apache.mina.core.session.IoSession;
import org.apache.mina.filter.codec.ProtocolCodecFactory;
import org.apache.mina.filter.codec.ProtocolDecoder;
import org.apache.mina.filter.codec.ProtocolEncoder;
import org.apache.mina.filter.codec.textline.LineDelimiter;
import org.apache.mina.filter.codec.textline.TextLineDecoder;
import org.apache.mina.filter.codec.textline.TextLineEncoder;

/** 
 * A {@link ProtocolCodecFactory} that performs encoding and decoding between 
 * a text line data and a Java string object.  This codec is useful especially 
 * when you work with a text-based protocols such as SMTP and IMAP. 
 * 
 * @author lidian
 * @version $Id: TextLineCodecFactory.java, v 0.1 2011-1-27 上午10:08:53 lidian Exp $
 */
public class TextLineCodecFactory implements ProtocolCodecFactory {
    private final TextLineEncoder encoder;
    private final TextLineDecoder decoder;

    /** 
     * Creates a new instance with the current default {@link Charset}. 
     */
    public TextLineCodecFactory() {
        this(Charset.defaultCharset());
    }

    /** 
     * Creates a new instance with the specified {@link Charset}.  The 
     * encoder uses a UNIX {@link LineDelimiter} and the decoder uses 
     * the AUTO {@link LineDelimiter}. 
     * 
     * @param charset 
     *  The charset to use in the encoding and decoding 
     */
    public TextLineCodecFactory(Charset charset) {
        encoder = new TextLineEncoder(charset, LineDelimiter.UNIX);
        decoder = new TextLineDecoder(charset, LineDelimiter.AUTO);
    }

    /** 
     * Creates a new instance of TextLineCodecFactory.  This constructor 
     * provides more flexibility for the developer. 
     * 
     * @param charset 
     *  The charset to use in the encoding and decoding 
     * @param encodingDelimiter 
     *  The line delimeter for the encoder 
     * @param decodingDelimiter 
     *  The line delimeter for the decoder 
     */
    public TextLineCodecFactory(Charset charset, String encodingDelimiter, String decodingDelimiter) {
        encoder = new TextLineEncoder(charset, encodingDelimiter);
        decoder = new TextLineDecoder(charset, decodingDelimiter);
    }

    /** 
     * Creates a new instance of TextLineCodecFactory.  This constructor 
     * provides more flexibility for the developer. 
     * 
     * @param charset 
     *  The charset to use in the encoding and decoding 
     * @param encodingDelimiter 
     *  The line delimeter for the encoder 
     * @param decodingDelimiter 
     *  The line delimeter for the decoder 
     */
    public TextLineCodecFactory(Charset charset, LineDelimiter encodingDelimiter,
                                LineDelimiter decodingDelimiter) {
        encoder = new TextLineEncoder(charset, encodingDelimiter);
        decoder = new TextLineDecoder(charset, decodingDelimiter);
    }

    public ProtocolEncoder getEncoder(IoSession session) {
        return encoder;
    }

    public ProtocolDecoder getDecoder(IoSession session) {
        return decoder;
    }

    /** 
    * Returns the allowed maximum size of the encoded line. 
    * If the size of the encoded line exceeds this value, the encoder 
    * will throw a {@link IllegalArgumentException}.  The default value 
    * is {@link Integer#MAX_VALUE}. 
    * <p> 
    * This method does the same job with {@link TextLineEncoder#getMaxLineLength()}. 
    */
    public int getEncoderMaxLineLength() {
        return encoder.getMaxLineLength();
    }

    /** 
     * Sets the allowed maximum size of the encoded line. 
     * If the size of the encoded line exceeds this value, the encoder 
     * will throw a {@link IllegalArgumentException}.  The default value 
     * is {@link Integer#MAX_VALUE}. 
     * <p> 
     * This method does the same job with {@link TextLineEncoder#setMaxLineLength(int)}. 
     */
    public void setEncoderMaxLineLength(int maxLineLength) {
        encoder.setMaxLineLength(maxLineLength);
    }

    /** 
     * Returns the allowed maximum size of the line to be decoded. 
     * If the size of the line to be decoded exceeds this value, the 
     * decoder will throw a {@link BufferDataException}.  The default 
     * value is <tt>1024</tt> (1KB). 
     * <p> 
     * This method does the same job with {@link TextLineDecoder#getMaxLineLength()}. 
     */
    public int getDecoderMaxLineLength() {
        return decoder.getMaxLineLength();
    }

    /** 
     * Sets the allowed maximum size of the line to be decoded. 
     * If the size of the line to be decoded exceeds this value, the 
     * decoder will throw a {@link BufferDataException}.  The default 
     * value is <tt>1024</tt> (1KB). 
     * <p> 
     * This method does the same job with {@link TextLineDecoder#setMaxLineLength(int)}. 
     */
    public void setDecoderMaxLineLength(int maxLineLength) {
        decoder.setMaxLineLength(maxLineLength);
    }
}
